Centrifugal governor for controlling the r.p.m. of diesel engines



United States Patent [72] Inventors Heinrich Staudt,

Markgroningen Weilertalhausen; H H Rolf IVIiilIer,Stuttgart-Zuffenhausen; Eberhard Hofmann, Kirchberg, Murr- Neuhof,Germany [21] Appl. No. 773,619

[22] Filed Nov. 5, 1968 [45] Patented Sept. 29, 1970 [73] AssigneeRobert Bosch GmbH,

Stuttgart, Germany [32] Priority Nov. 14, 1967 [33] Germany [54]CENTRIFUGAL GOVERNOR FOR CONTROLLING THE RPM OF DIESEL ENGINES [50]Field ofSearch 123/32, 119, 139, 140; 74/526 [56] References CitedUNITED STATES PATENTS 2,818,053 12/1957 Shallenberg 123/140 3,130,5994/1964 Haasm, 74/526 Primary Examiner Laurence M. GoodridgeAttorney-Edwin E. Greigg ABSTRACT: In a diesel engine, a centrifugalgovernor is connected (1 by a first linkage means to the control rod ofafuel injection pump to cause displacement of said rod thereby varyingthe fuel delivery and (2) by a second linkage means to an adjustableabutment which limits said displacement and 7 Claims 1 Drawing thuslimits the maximum fuel delivery under various operating [52] U.S.Cl...123/140 conditions. The position of said adjustable abutment is inde-[51] Int.Cl F02d 1/04 pendentofthe position ofsaid firstlinkage means.

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. 4 Patented Sept. 29, 1970 3 5 8 5 VIII! lNVf/VTORS h'l'm'l'ch STAUDTEberhard l/OFHAN/V Rolf MIJZIER CENTRIFUGAL GOVERNOR FOR CONTROLLING THERPM OF DIESEL ENGINES BACKGROUND OF THE INVENTION The invention relatesto a centrifugal governor for controlling the r.p.m. of diesel enginesby means of a connecting linkage which, on the one hand, is inengagement with the regulator member displaced by the governor weightsas a function of the rpm. and, on the other hand, is connected with thefuel delivery control rod of the injection pump. The displacement of thefuel delivery control rod is, in the direction of increasing fuelquantities, limited by an adjustable stop determining a maximum fueldelivery. An accumulator (a spring-type storage device) is loaded assoon and as long as the said connecting linkage tends to displace thesaid fuel delivery control rod beyond said stop or abutment.

Various centrifugal governors of the above outlined structure havealready been known. Such devices are described, for example, in GermanPat. No. l,0l0,32l and U.S. Pat. No. 2,259,693.

In these centrifugal governors the adjustable stop is coupled with saidconnecting linkage and is therefore affected by the position thereof.Stated in other terms, the adjustable stop is shifted with respect to acooperating abutment plate fixedly secured to the housing and providedwith various abutment faces every time the connecting linkage moves.

OBJECT AND SUMMARY OF THE INVENTION It is an object of the invention toprovide an improved centrifugal governor arranged in such a manner thatthe adjustable abutment determining the maximum fuel delivery, is notattached to the connecting linkage and is, consequently, not

affected by the position thereof. The position of the adjustable stop isthus dependent exclusively on the position of the centrifugal weights.

:In order to achieve the aforenoted object, according to the invention,between the centrifugal weights and the regulator member displaceablethereby, there is inserted a transfer element shiftable by thecentrifugal weights and coupled with an I DESCRIPTION OF THE PREFERREDEMBODIMENT To the drive shaft 1 ofa fuel injection pump (not shown) fordiesel engines there is secured a face plate 2 on which there arepivotally mounted centrifugal weights 3. The radially inwardly extendingarms 4 of the weights 3 engage the frontal face 5a of a roller bearing 5which is slidably mounted on a stub 1a of the drive shaft 1. The rollerbearing 5 transmits the displacing forces of the centrifugal weights 3to a transfer element or adaptor sleeve 6 also slidably mounted on thestub shaft la. The adaptor sleeve 6 receives in a coaxial annular cavityan adaptor spring 7 transmitting the adjusting forces from the adaptorsleeve 6 to the regulator member 8, as will be described in greaterdetail later. To opposed sides of the regulator member 8 there arefixedly secured in axial alignment pins 9 and 10 which, respectively,are slidably held in axial bore lb of stub la and in axial bore 11b ofaspring seat base 11. The spring seat base 11, in turn, is axiallydisplaceahly held in a socket 12 which threadedly engages a base plate13 forming part of a housing 13a shown only in broken lines. Withinsocket 12 there is disposed a control spring 14 which engages, on theone hand, the spring seat base 11 and,

on the other hand, a spring seat disc 15 threadedly held in the socket12. Through the spring seat disc 15 there passes an axial adjustingscrew 16 which, in turn, serves as a seat for an idling spring 17. Atits other end, the spring 17 engages the terminal face of pin 10. As aconnecting linkage between the regulator member 8 and a fuel deliverycontrol rod 18 of the fuel injection pump, there is provided a shiftlever 19, a regulator lever 20, and a guide rod 21, which latter carriesa spring-type accumulator generally indicated at 30. The shift lever 19has a pin 22 by which it is held in a forked extension 23a of a radialbolt 23 extending through and secured to the regulator member 8. Theshift lever 19 is pivotally secured to a bearing pin 24 fixedly held inhousing 13a and is articulatedly connected to one end of regulator lever20. A pin 25 secured to an adjusting link 26 extends into a guiding slot20a of the regulator lever 20. The adjusting link 26 is, in a bell-crankmanner, connected through a shaft 27 secured to housing 13a with anexternally operable adjusting lever 28 disposed outside of the housing13a, The guide rod 21 which is pivotally connected to the regualtorlever 20 transmits the adjusting movements of the latter through aspring-type accumulator 30 to an arm 29 rigidly affixed to the controlrod 18. If the control rod 18 abuts against a stop during itsdisplacement in either direction and if, thereupon, the guide rod 20continues its adjusting motion in the same direction, the spring 31 ofthe accumulator 30 is compressed from one or the other direction.

For stopping the control rod 18 in the direction of full load, there isprovided a contour plate 34, the curved edge of which is adapted to beengaged by a finger 29a secured to and protruding from the arm 29. Saidedge, as will be seen later, is formed of two consecutivecurve-portions: one is associated with additional fuel delivery forstarting while the other is an adaptor-curve assisting in the control offuel subsequent to the starting phase of the engine. The contour plate34 is provided with a guiding slot 34a into which extends a cam 35mounted on an eccentric 36 which, in turn, is affixed to the end face ofa shaft 37 rotatably held in housing 13a. When shaft 37 is turned, theposition of eccentric 36 changes. The contour plate 34 is slidable withrespect to cam 35 and substantially parallel to arm 29. For displacingthe contour plate 34 dependently of the adaptor sleeve 6, butindependently of the motion of regulator member 8, there are providedtwo levers 38 and 39 both pivotally attached to a common pin 40 fixedlysecured to the housing 13a. The lever 38 pivotally engages with a forkedend 38a a pin 6b affixed to a lug 6a which, in turn, is secured to theadaptor sleeve 6. With its end remote from the forked end 38a, the lever38 transmits the adjusting motion of the adaptor sleeve 6 to lever 39through the interposed drag spring 41 which, on the one hand, engages anangularly offstanding extension 38b of the lever 38 and, on the otherhand, contacts a spring seat 39a affixed to lever 39. The spring seat39a has a curved extension 39b which is adapted to engage the lever 38and thus limits the pivotal motion of the lever 39 with respect to pin40. The lever 39 is held in a forked terminus 42a of a connecting bolt42 which, in turn, is slidably held in two aligned openings provided,respectively, in spaced flanges 34b and 340 extending normal to thecontour plate 34. The connecting bolt 42 is adjustable with respect tothe contour plate 34, in a direction parallel to the length dimension ofguiding slot 34a, by means of a nut 43 threadedly engaging theconnecting bolt 42 and lying against the upper face of flange 34b of thecontour plate 34. Between the spring seat 44 secured to the shaft of theconnecting bolt 42 and the lower face of flange 3417 there is compresseda coil spring 45 surrounding the connecting bolt 42. A purpose ofproviding levers 38 and 39 in the linkage that couples the adaptorsleeve 6 with the contour plate 34 is to obtain, at terminus 42a, adisplacement that is larger than that of adaptor sleeve 6.

OPERATION OF THE PREFERRED EMBODIMENT The movable parts of thecentrifugal regulator are shown in the position which they assume whenthe engine is stationary and the externally operable adjusting lever 28is in its shut-off position.

For starting the engine, the driver moves the externally operableadjusting lever 28, and thus, the adjusting link 26, the control lever20, the guide rod 21, the arm 29 and control rod 18 are displaced fromthe inoperative position shown in the figure into the full loadposition, whereby finger 29a is brought into contact with curve-portion34' which determines the upper limit of the fuel delivery for start.

After the start of the engine, first the outwardly swinging centrifugalweights 3 shift the adaptor sleeve 6 and the regulator member 8 to theright. The latter is displaced directly by the adaptor spring 7 withoutcompression thereof. Due to the said displacement of regulator member 8,the idling spring 17 is continuously and increasingly compressed by thepin 10 until the regulator member 8 abuts against the outer terminalface of spring seat base 11. As the adaptor sleeve 6 moves to the right,it causes lever 38 to rotate counterclockwise and, through spring 41, topush down on lever 39. As a result, the contour plate 34 is pulleddownwardly through a determined distance and the curved edge of thecontour plate 34 displaces follower nose 29a, arm 29 and control rod 18to the right. Thus, the additional fuel delivery required for startingis shutoff.

If the rpm of the engine continues to increase, then beyond apredetermined rpm the adaptor spring 7 is, due to the increasing forcesof the centrifugal weights 3, continously and increasingly compresseduntil the adaptor sleeve 6 abuts against the regulator member 8. ln thisrpm. range, in which only the adaptor sleeve 6 is displaced, the contourplate 34 is further pulled down until the upper terminal edge of guidingslot 340 eventually abuts against the cam 35. Thus, under full loadconditions in which the finger 39a engages the upper curve-portion 34"which limits the full load fuel delivery, for each r.p.m. anothermaximal fuel delivery may be set. Since in full load condition the guiderod 21 is held immobile by the driver, the length of spring 31 of theaccumulator 30 changes by virtue of the motion of arm 29 caused by thecontour plate 34.

By suitably selecting the length ratio of levers 38 and 39, adisplacement of contour plate 34 may be obtained which is large withrespect to the relatively short shift the adaptor sleeve 6 executes inrelation to regulator member 8. Consequently, the extent of travel offinger 29a with respect to and on the curved edge portion of contourplate 34 will be relatively large.

If the rpm. increases further, the spring seat base 11 is displaced tothe right by the adaptor sleeve 6 and by the regulator member 8, wherebythe control spring 14 is compressed. During this last-named motion, thecontour plate 34 is prevented by the cam 35 from executing a furtherdownward displacement; as a result, the drag spring 41 is compressed. Itis thus seen that by using drag spring 41, the travel of contour plate34 may be limited without interfering with the motion of adaptor sleeve6.

The r.p.m. control device described hereinabove not only ensures bysimple means the required additional fuel delivery for good startingconditions, but also provides for a relatively easily adjustableadaptation of the fuel quantities to be injected in the full load range.By means of turning the shaft 37 the control path for full loadconditions may be set, while by adjusting the nut 43 the shut-off pointof the addtional fuel delivery for starting conditions and the beginningof the adaptation of the fuel quantities for full load conditions may beregulated.

The shaft 37 may be actuated by control mechanisms which are arrangedexternally of the centrifugal governor and may operate dependent uponatmospheric and temperature conditions.

We claim:

1. In a centrifugal governor for controlling the rpm. of diesel engines,said governor including weights displaced as a function of the rpm. ando eratively connected through a governor member to a contro rod ofa fuelin ection pump for regulating the delivery thereof by displacing saidrod along a path, coupling means connecting said weights with anadjustable abutment determining the maximum fuel delivery of saidinjection pump by limiting said path, the improvement in said couplingmeans comprising:

A. a transfer element slidably disposed between said governor member andsaid weights and being displaceable by the latter; and

B. an adaptor spring connecting said transfer element with said governormember for transmitting the displacing forces of said weights from saidtransfer element to said governor member, said adjustable abutment beingunaffected by the position of said governor member.

2. The improvement as defined in claim 1, wherein said transfer elementis an adaptor sleeve slidably mounted on a drive shaft stub anddisplaceable thereon along a path coinciding with the path ofdisplacement of said governor member.

3. The improvement as defined in claim 2, wherein said drive shaft stubhas an axial bore, said governor member is provided with a pin rigidlysecured thereto and axially extending therefrom, said pin is slidablydisposed in said bore.

4. The improvement as defined in claim 1 including a first and a secondlever both pivotable about a fixed common joint, said first lever is, atone end, pivotally secured to said transfer element and engages with itsother, angularly bent end said second lever through a drag spring fortransmitting the motion of said transfer element from said first leverto said second lever, said second lever is, at its end spaced from saidcommon joint, coupled to said adjustable abutment.

5. The improvement as defined in claim 1, wherein said adjustableabutment is formed of a contour plate having a curved edge adapted to beengaged by a follower secured to said control rod, said contour plate isprovided with a guide slot slidably engaged by a cam.

6. The improvement as defined in claim 5, wherein said cam is mounted onan eccentric affixed to the terminal face of an externally operableshaft.

7. The improvement as defined in claim 4, wherein said second lever iscoupled to said abutment by means of a bolt slidably secured to saidabutment, said bolt is adjustable with respect to said abutment by anadjusting nut threadedly engag ing said bolt.

